Bug when using the HTML Tag "<progress></progress>" (only when switching to Visual Editor)

[Sprax2013]

When I go to Text (in Editor) and write use "<progress>" from HTML to create a Progress Bar, it will be displayed on the Webside. But when I edit it agan or switch to Visual (in Editor) the progrss-Tag will be removed and when saving also on website. Please Fix or create a nice Addon

[swissspidy]

The visual editor only allows for a limited set of HTML elements. <progress> is kinda unusual and probably not allowed by default in TinyMCE. This sounds reasonable to me, as the <progress> alone isn't very useful.

You can hook into the tiny_mce_before_init filter to modify the extended_valid_elements setting.

[sabernhardt]

The TinyMCE editor needs to be extended to support the progress tag. One way is with the tiny_mce_before_init filter (in a custom plugin).

A more user-friendly way is with the ​Advanced TinyMCE Configuration plugin. On the settings screen, you could add ,progress[id|max|value] to the extended_valid_elements setting to support the tag and a few of its typical attributes.